Spark-plug



. UNITED STATES? PATENT OFFICE.

WILLIAM E. JACQUES,r OF LAKELAND,FLORIDA.

SPKRK-PLUG.

Specification of Letters Patent.

Patented oet. 14, 1919.

- Application led April 21, 1917. Serial No. 163,732.

To all whom z't may concern:

Be it 'known that I, WILLIAM E. JACQUES, a citizen of the United States, and a resident of. Lakeland, in the county of Polk and State of Florida, have invented a certain new and useful Improvement in Spark- Plugs, of which the following is aspecificaadapted for application to the same.

tion.

The present invention relates to internal combustion engines, 'and has particular reference to a novel construction of spark plug An objectof the present invention is to provide-a simplified and durable construction of spark plug. whichmay be economically produced and soldat a relatively low cost. v

Another object of the present invention is to providea spark plug having a singleelectrode adapted to coperate with the ad- `jac'entwall ofthe cylinder of the engine when the spa-rkplug is in position to-form the spark gap, and the provision of a pef culiarmounting for the' single electrode and its stein for varying the distance between the? electrode and the wall of the cylinder for varying the spark gap. f

The invention further aimsat the provision of a spark plug'comprising relatively few parts which are of novel construction,

and assembled in a novel manner.

' fragmentarily and in vsection-.

The above, and various other objects and advantages of this invention wi-llbein part -described, and in 'part understood, from the detailed description of the pres` followin ent pre erred embodiment,thesaine being illustrated in the accompanyingdrawing wherein:

.Figure 1 'is a longitudinal section'through -a spark'plug constructed'v according tothe present invention and as applied to the wall or head of a cylinder, the latter being shown Fig.' 2 is a side ele'vation of the spark plig.

ig. 3 is anv inner end vlew'of the same. Fig. 4 is an 'outer end View of the plug.

Fig. 5 is a transverse section taken through the plug substantially onthe line 5--5 of Fig. 2,*lookingin the direction of the arrows.

is provided inV the usual manner with a,"

Referring to this drawing, A designates the wall or head of a cylinder which may be of any suitable construction, and which -body 10 and prevent the tllireaded bore B adapted to receive a spark p ug.

The spark plug comprises a barrel 10 which may be in Ythe form of an externally threaded casting provided upon -its outer end with an outstanding angularly faced flange 11 adapted to receive a wrench or the like for screwing the barrel 10 into and out of the bore B of the cylinder wall A. The

barrel l0 is provided with an axial 'openet.A

ing which preferably tapers from its linner to its outer end, and is adapted to receive. therein a corresponding tapered corez 12 preferably formed from insulating material, such `as porcelain or the like. The core 12 is packed or sealed in the barrel 10, by the provision of a iller 13 of cement or the like adapted to hold thevcore 12 rigidl wardly through the plug.

The core 12 is provided with a longitudinal opening therethrough eccentric to the central axis of the core, and through which is passed a stem 14 formed of a single length" i eoj` of Wire of the' desired gage adapted to fit tightly in the 'core-12. The core 12 may be molded and compressed about the stem 14in the manufacture of the plug, and the lower end of the stem 14 is provided with oppositely extending lugs or projections 15- formed by swaging or pressing portions of inthe passage o gas up' the stem body outwardly at the lower end thereof. The vlower extremity of the stem 14, beyond the projections 15, is bent laterally at substantially right angles to theaxis of the stem 14 to provide an electrode 16 the extremity of which approaches'the adv the core 12 to prevent egress of ases through thev plug. The outer end o the broad head 17 which is apertured forthe reception of the terminal portionof a Wire C forming one side of the high tension cir cuit. The head 17 and the outer end of the stem 14 are of suliicient length beyond the outer end of the core 12. to receive a U- 4by asuitable tool, it is' tightly'clamped in .s1-cm -12 is provided with 'a relatively Hat iro y shaped spring clip 18 thereon beneath the wire C, the outer portion of the clip 18 engaging the wire C and binding it in the opening through the head 17. The clip 18 is in the form of a strip of spring metal which is overturned upon itself andprovided with elongated openings in its opposite arms which register and through which may freely extend the head 17 and the outer end of the stem 14. The stem 14: is thus yieldingly held in the core 12 by the clip 18, and the wire C yieldingly held in the head 17 by the clip. Preferably, the outer end of the core 12 is rounded or convexed to conform to the concaved flaring side of the clip 18 to forni a frictional bearing surface for the clip and prevent the turning thereof on the core, and the elongated openings in the arms of the clip are of a width less than the width of the head 17 to hold the latter from turning in the clip. The clip 18 therefore holds the stem 14 yieldingly in 4adjusted position to prevent the accidental turning of the stem by the vibration of the engine when running. A gasket 19, in the form of a packing ring, surrounds the barrel when immediately beneath the flange 11 and is adapted to seat against the outer face of the cylinder wall A to seal the barrel 10 therein when the vplug is in position.

It may be thus noted that the spark plug of this invention may be economically oonstructed from relatively cheap material, and that it comprises relatively few parte. It is also rovided with a novel arrangement. or intergitting of the parte to secure the desired adjustment without the bending or the breaking of the electrode 16, the adjustment being a minute one so as to obtain a sparlr gap of the desired dimension. The stem and the electrode are formed from a single length of relatively small Wire which is swaged or stamped out to form the shoulder or abutment at its lower end, and the core 12 may be molded about the Wire after the shoulder is formed, fits the wire snugly and practically seals the wire in the core. This frictional contact between the core and the stern or wire 14 is such as to yieldingly hold the stem in ad- Justed position, and coperates with the spring clip 18 in retaining the electrode 16 at the desired radial adjustment with respect to the axis of the stem. By utilizing the side wall of the cylinder as one side of the circuit, or an electrode, the number of parts of the plug are considerably reduced, and a relatively Strong durable and economically constructed plug is produced. i

It is of course understood that various changes and modifications lma be made in the details of construction an in the selection of materials of the above-specifically described spark plug without departing from the spirit of the invention, and being restricted only by the scope of the following claims. 'i

I claim 1. In a spark plug, the combination of a barrel adapted to be screwed in a cylinder wall and provided with an outwardly taperlng axial opening, a correspondingly tapered core sealed in said opening, a stem extending longitudinally and eccentrically through said core, and an electrode projecting laterally through the inner end of the cylinder and approaching said cylinder wall, said stem being adapted to be turned in said core to varythe size of the s ark gap between said electrode and said cyllinde'r wall.

2. In a spark plug, the combination of an externally threaded barrel adapted for en- .Gagement in a cylinder wall, a tapering core tting in said barrel, a seal between said core and said barrel to retain the core therein, and an eccentrically mounted stem projecting longitudinaliy through the core and provided with a laterall turned inner end forming an electrode a apted to approach the cylinder wall when the plug is in posi tion, said stem being adapted to be rotated to move the extremity of the electrode toward and from the cylinder Wall.

WILLIAM E.- JACQUES. 

